1. Technical Field
The present disclosure relates to printing machines. In particular, the present disclosure relates to monitoring modules, e.g., consumer replaceable units (herein after referred to as “CRUs”), of printing machines utilizing RFID tags attached thereto.
2. Description of the Related Art
Automatic Identification and Data Capture, also known as AIDC, refers to the method of automatically identifying objects, collecting data about them, and entering that data directly into computer systems (or other mediums of storage) with minimal, or no, human involvement. AIDC technologies include barcodes, and radio frequency identification (RFID). An AIDC device is a device for reading, and/or writing, data encoded in AIDC media, such as a barcode scanner for reading data encoded in a barcode, or an RFID interrogator for reading and/or writing data encoded in an RFID tag.
RFID is a method for automatic identification which uses radiofrequency (RF) signals. A device known as an RFID interrogator which includes an RFID writer and/or a RFID reader, wirelessly reads, and optionally, writes data stored in a transponder, known as an RFID tag, that is physically attached to an article, such as a product, packaging or shipping container. Typically, an RFID tag consists of two main components: an integrated circuit (IC) for storing and processing data and for modulating and demodulating the RF signal, and an antenna coupled to the chip that enables the chip to exchange data between the tag and interrogator. An RFID tag can be read-only, wherein the IC contains unalterable data, such as a unique identification code indelibly encoded by the tag manufacturer which is used to uniquely identify the tag. Alternatively, an RFID tag can be read-write, wherein the stored data can be changed or deleted. Typically, however, a read-write RFID tag will also contain read-only data, such as an indelible unique identification code, so that individual tags can be uniquely identified.
RFID tags ordinarily range in sizes from several inches to sizes no larger than a grain of rice. RFID tags can be constructed using an essentially planar form factor and incorporated into a self-adhesive label, for example. It is expected the ability to print RFID tags, much like a barcode is printed, will eventually become widespread using, for example, techniques developed by Xerox for depositing liquid polythiophene semiconductors onto a surface at room temperature.
RFID tags fall generally into three categories: passive RFID tags, in which the IC is powered entirely by the minute current induced in the antenna by the RFID interrogator's signal and where the transmitted RF signal is generated by backscattering the interrogating signal; active RFID tags, in which the IC and the RF transmitter are powered by an included power source, such as an internal battery; and semi-active RFID tags, in which the IC is powered by an included power source while the transmitted RF signal is generated by backscattering. RFID tags typically operate in one of five RF bands: in the low frequency (LF) range of 125-135 KHz, in the 13.56 MHz high frequency (HF) region, in the ultra high frequency (UHF) range of 868-930 MHz, in the 2.45 GHz microwave region, and in the 5.8 GHz microwave region. RFID tags are operational at distances ranging from a few inches to several yards in the case of passive tags, while active tags can operate at distances of over a quarter-mile.
Additionally, sensors can be included in an RFID tag to enable the tag to measure and record temperature, humidity, G-forces, radiation, and/or other environmental phenomena, which can thereafter be read by the interrogator to determine whether the tagged item has been exposed to extreme or undesirable conditions. Such RFID tags are commonly used in, for example, the shipment and handling of perishable, fragile or sensitive items. An RFID tag can also have the ability to be rendered permanently inoperable upon receiving an appropriate “self-destruct” command from the RFID interrogator. Demand for these kinds of creative solutions (and other solutions) utilizing RFID tags has continued to be strong in recent years.